فهرست مطالب sahand jorfi

The Fe3O4/MW-CNT composite was prepared for a hybrid photo-catalyst-assisted electrochemical process for the removal of BTX contamination from wastewater. Oxidation of multi-walled carbon nanotube was conducted by different treatments including acid treatment and hydrogen peroxide. The XRD, FTIR, SEM, TEM, and BET analyses were performed to characterize both the MW-CNT and the synthesized composite. Simultaneous photo-catalyst and electrochemical processes were conducted to evaluate the performance of a new hybrid process for wastewater treatment. The effect of current density, photo-catalyst loading, and BTX initial concentration was investigated experimentally. The characterization results of the synthesized composite show that a mixture of strong nitric acid and sulfuric acid treatment at a high exposure time and low temperature is the best route for MW-CNT oxidation. The removal efficiency of BTX compounds from wastewater using the hybrid photo-electrochemical process was found to be in the range of 28 to 43% for different conditions. The optimum condition for maximum removal of BTX was found by mathematical modeling of experimental data. The results indicate that a combination of photo-catalyst and the electrochemical process can enhance the BTX removal efficiency.

The majority of insecticides target sodium channels. The increasing emergence of resistance to the current insecticides has persuaded researchers to search for alternative compounds. Scorpion venom gland as a reservoir of peptides or proteins, which selectively target insect sodium channels. These proteins would be an appropriate source for finding new suitable anti-insect components.

Transcriptome of venom gland of scorpion M. eupeus was obtained by RNA extraction and cDNA library synthesis. The obtained transcriptome was blasted against protein databases to find insect toxins against sodium channel based on the statistically significant similarity in sequence. Physicochemical properties of the identified protein were calculated using bioinformatics software. The 3D structure of this protein was determined using homology modeling, and the final structure was assessed by MD simulation.

The sodium channel blocker found in the transcriptome of M. eupeus venom gland was submitted to the GenBank under the name of meuNa10, a stable hydrophilic protein consisting of 69 amino acids, with the molecular weight of 7721.77 g/mol and pI of 8.7. The tertiary structure of meuNa10 revealed a conserved CS-alpha/beta domain stabilized by eight cysteine residues. The meuNa10 is a member of the 3FP superfamily consisting of three finger-like beta strands.

This study identified meuNa10 as a small insect sodium channel-interacting protein with some physicochemical properties, including stability and water-solubility, which make it a good candidate for further in vivo and in vitro experiments in order to develop a new bioinsecticide.

The emergence and spread of SARS-CoV-2 has increased environmental disinfectant usage to reduce the transmission of this virus. Ethanol 70-90% and 5% sodium hypochlorite have the highest consumption for disinfection of various environmental surfaces during the COVID-19 pandemic. Dental unit waterlines (DUWLs) are more susceptible to microbial contamination due to their particular structure. This study aimed to investigate the effect of increasing the use of disinfectants during the COVID-19 pandemic on the bacterial contamination of DUWLs.

During November (before the COVID-19 pandemic) and December (during the COVID-19 pandemic), a questionnaire was used to assess the frequency of disinfection of unit surfaces and other environmental surfaces and the type of disinfectants used. The water samples were collected from different parts of DUWLs. The gram staining method followed by the biochemical method was used to identify the desired bacteria.

The results showed that the frequency of disinfection of dental units increased 8 times in December compared to November. There is a significant inverse relationship between the frequency of disinfection of dental units surfaces and the bacterial contamination of dental unit waterlines.

The microbial load in different parts of the DUWLs was less than 200 CFU/mL. The American Dental Association (ADA) recommended and indicated the allowable microbial concentration and the appropriate quality and water used in these units.

This study examined the removal of ciprofloxacin (CIP), which is a very widely used antibiotic, from an aqueous medium by applying AgI/Ag2O photocatalyst under visible light radiation.

AgI/Ag2O was synthesized conveniently by applying a two-stage precipitation method. The synthesized compound was characterized by X-ray powder diffraction (XRD), FE- field emission scanning electron microscopy (FE-SEM), energy dispersive x-ray (EDX), and UV-Vis spectrophotometry. Different parameters including initial pH of the solution, initial CIP concentration, reaction kinetics, and catalyst reusability were investigated.

Concurrent use of AgI and Ag2O caused improved photocatalytic properties in the presence of UV light. The pH and initial concentration of CIP affected the process efficiency; 95% efficiency was achieved within 100 min at pH 9. Furthermore, the process efficiency was still maintained over 90% after four consecutive cycles.

The photocatalytic degradation process using AgI/Ag2O nanocomposite under visible light radiation is a suitable method for removing CIP from aqueous media due to its high efficiency and stability.

The purpose of this work is to study degradative removal of gentamicin antibiotic from aqueous media that a trace amount of it may present a human health risk. To this aim photocatalytic process using a recyclable magnetic titania photo-catalyst was utilized. The Nano-catalyst was synthesized, characterized, and utilized to remove gentamicin antibiotic. The process modeling and optimization were performed by a second order polynomial model using design of experiment software. According to the model prediction, the process can remove gentamicin antibiotic up to 94.7% in the optimum condition. The introduced optimum conditions were; initial pH = 6.9, [gentamicin] = 20 ppm, [Catalyst] = 195 mg, and time = 63 min. Mineralization of the gentamicin was also investigated such that in the optimum condition 51.3% mineralization efficiency was obtained in optimum condition. Kinetic study results showed that the data was well fitted by pseudo first order kinetic model. Also, the effect of sulfate and chloride ions as radical scavenger on removal efficiency was assessed and process efficiency was reduced by using chloride and sulfate.

Many bioremediation strategies have been developed to help improve soil clearance from oil and its derivatives. The use of native bacteria to decompose crude oil-contaminated soils has been studied by many researchers. Along with this line of research, in the present study, a consortium of bacteria isolated from three different soil types in the Khuzestan region was used after identification. Finally, the optimal conditions for bioremediation of each soil type were determined. The results showed that the isolated strains were five unique strains, including Cupriavidus metal lidurans, Bacillus pacificus, Lysinibacillus fusiformis, Brevibacillus borstelensis, and Ralstonia metallidurans. These had good growth potential in contaminated soils and could effectively reduce TPH. Among the factors examined, the amount of moisture and nitrogen were two essential factors that reduce the amount of TPH. In optimal conditions, the moisture percentage was 135, 147, and 142, and the input nitrogen was 512 ppm, 513 ppm, and 617 ppm, for three types of soil, in Andimeshk, Ahvaz, and Abadan, respectively. NH4NO3, as the best source of nitrogen, had the best performance. In confirmatory experiments with 2.5% crude oil in optimal conditions, the rate of TPH reduction after 56 days was 48.4%, 53.4% and 56.4% for Abadan, Ahvaz, and Andimeshk soils, respectively. This study confirms the efficiency of native bacteria isolated from the soils of Khuzestan province for biodegradation of crude oil and introduces Bacillus pacificus bacteria as a new species that can bioremediation.

Several recent studies have focused on leaching pesticides from agricultural soils into surface and groundwater resources during irrigation. As a result, information about herbicide residues in water was necessary for conserving related resources. This study provided an overview of monitoring herbicides in water resources worldwide. In this scoping review, five databases were searched for publications (1990 to April 2021), including Scopus, PubMed/Medline, Cochrane library, Embase, and Web of Science. Among the 394 identified articles, 17 papers were selected for inclusion. Most of these studies have been conducted in regions with low herbicide concentrations, including Spain, Greece, Canada, Brazil, Hungary, Malawi, Portugal, Lesotho, Germany, Serbia, and the USA. The high-level alachlor, metolachlor, atrazine, metribuzin, and simazine herbicides in groundwater were detected in Portugal (0.4-13μg/L). An overview of studies demonstrated that herbicides are widely used in water resources, and surface waters are more contaminated than groundwaters.

Photocatalytic oxidation using novel photo-catalysts has been considered as an effective method for destruction of recalcitrant organics. In this study, photocatalytic degradation of 4-chlorophenol (4-CP) using lanthanum Oxide nanoparticles (LONPs) was investigated under UVC/Vis irradiation. Effect of operational parameters including pH (2 – 11), catalyst content (250-3000 mg L-1), contact time (20 - 180 min) 4-CP concentration (25- 400 mgL-1) were investigated according to one factor at the time experimental procedure. Highest removal efficiency of 4-CP was observed at pH =7. Result was indicated that the removal of 4-CP was increased from 76% to 92%, with increasing catalyst dosage from 0.25 to 1 g L-1. Then, a decrease was observed in 4-CP removal with an enhancement in catalyst dosage from 1 to 3 g L-1. Highest 4-CP removal (98%) was observed at the initial concentration of 25 mg L-1. At the contact time from 20 to 60 min, removal efficiency of 4-CP was increased from 24% to 64%, respectively. The contact time was increased to 120 min, removal efficiency of 4-CP was increased to 100%. Therefore, the optimal reaction time was 100 min. The AOS indices was showed an increasing trend of mineralization. In other words, the process of degradation of 4-CP was improved with photocatalytic degradation by UVC-La2O3. Among the kinetic models, the pseudo-first order model due to the highest correlation coefficient of R2 = 0.991 for the La2O3-UVC process.

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this systematic review, five databases were searched (Scopus, PubMed-/Medline, Cochrane library, Embase, and Web of Science) for publications between 2019 to 12 February 2021. From 575 articles identified, seven papers were selected for inclusion. In the present paper, corona transmission routes from three environments of water, wastewater and air were considered. The most important transmission route of COVID-19 is through the air, which takes place from the following two routes: respiration and contact. Respiratory drops are caused by coughing and sneezing. Anyone who comes in close contact with someone having COVID-19 symptoms (sneezing, coughing, etc.) is potentially at risk for droplets. In this paper, corona transmission pathways from water, wastewater, and air in three environments were investigated. The results showed that the virus is transmitted through the air and its transmission through water and wastewater has not been proven. While the virus may survive in drinking water, there is no evidence that human coronavirus is present in surface and groundwater sources, or transmitted through contaminated drinking water. There is also no evidence of SARS-CoV-2 transmission through the sewage system, with or without wastewater treatment. Detection of this virus is very effective in determining the necessary and timely strategies to prevent further transmission of virus, and help to break the chain of COVID-19 transmission through water and wastewater.

Natural organic matters such as humic acid react with chlorine and produce disinfection by products such as trihalomethanes that are carcinogenic. In this study, shellfish ash was used as a novel adsorbent for removal of humic acid.

The present study was performed under various laboratory conditions including pH, adsorbent dose, contact time, and initial concentration of humic acid. Residual concentrations of humic acid in the samples were determined by a UV-Vis spectrophotometer at 254 nm wavelength. Artificial neural network (ANN) modeling studies were also performed.

Elemental analysis showed that the shellfish ash was 98% pure calcium. It was indicated that the maximum adsorption capacity was achieved in acidic conditions (pH = 3) and pHzpc was found to be 10.3. The adsorption data followed the Langmuir model (R2 > 0.9). The adsorption of humic acid followed the pseudo-second-order kinetic (R2 = 0.999). ANN modeling also provided the accurate prediction of humic acid adsorption for testing data (R2 = 0.989).

According to the results, shellfish ash is recommended as an effective biosorbent for removal of organic pollutants such as humic acid.

The purpose of this study was survey on 2,4-D concentration in Ahvaz drinking water in 2018-2019. A descriptive cross-sectional study was based on 10- month sampling program (from December 2018 to September 2019) in six points of distribution networks were conducted. All measured concentrations were less than the maximum allowable concentrations recommended by the National Standards Organization of Iran (1053) and WHO guidelines. In this study, the total THMs determined in autumn, winter and spring ranged from <0.004-2.98μg/L, 0.02-2.41μg/L and 0.01-0.04μg/L, and in summer less than the LOD, respectively. Different studies have shown that pesticides residue concentration in water samples have a relationship with the amount of pesticides used in an area, physical and chemical refractory properties of pesticides and environmental conditions. Thus, using resistant pollutants such as pesticides will be a serious threat to health of water consumers if they are not properly controlled.

of the Study: Pesticides are widely used in the agricultural sector to control pests. Based on numerous studies, the presence of pesticide residues in food causes a wide array of diseases.  The current study aimed to identify pesticide residues in foods of vegetal and animal origin and presented the methods used to reduce pesticide content in food before consumption.

For the purpose of the study, the articles published within 2008-2018 were searched in the local and international databases, including PubMed, Science Direct, Scopus, using the keywords of pesticides, food, Iran, and residual, in both Persian and English languages. The current study focused on pesticide residues in foods of vegetal and animal origin. Furthermore, this study discusses the methods used to reduce residual pesticide before consumption. The preliminary search yielded 185 articles. After reviewing the articles, 26 studies were finally selected considering the purpose of the study.

As evidenced by the obtained results, diazinon pesticide residue has been reported in many products. Pesticide residues were more frequently found in foods of vegetable origin, compared to those of animal origin. Effective factors influencing the presence of pesticide residues in food products include: farmers' unawareness, incorrect use of pesticide and inappropriate spraying, and disregard for the preharvest interval. Proper washing and immersion in alkaline solutions at a suitable time should be considered to decrease pesticide residues in food products before consumption.

The consumption of food products containing pesticides is associated with a variety of risks to humans, including nervous system dysfunction, reproductive disorders, brain damage, mental illness, and respiratory system disorder. The impact of pesticide residues can be minimized by training and awareness of farmers, Proper washing food products before consumption and as well as the supervision of executive organizations are the keys to the reduction of pesticide application in foods.

Biodegradation of hydrocarbon compounds is a great environmental concern due to their toxic nature and ubiquitous occurrence. In this study, biodegradation potential of oily soils was investigated in an oil field using indigenous bacterial consortium.

The bacterial strains present in the contaminated and non-contaminated soils were identified via DNA extraction using 16S rDNA gene sequencing during six months. Furthermore, total petroleum hydrocarbons (TPH) were removed from oil-contaminated soils. The TPH values were determined using a gas chromatograph equipped with a flame ionization detector (GC-FID).

The bacterial consortium identified in oil-contaminated soils (case) belonged to the families Halomonadaceae (91.5%) and Bacillaceae (8.5%), which was significantly different from those identified in non-contaminated soils (control) belonging to the families Enterobacteriaceae (84.6%), Paenibacillaceae (6%), and Bacillaceae (9.4%). It was revealed that the diversity of bacterial strains was less in oil-contaminated soils and varied significantly between case and control samples. Indigenous bacterial consortium was used in oil-contaminated soils without need for amplification of
heterogeneous bacteria and the results showed that the identified bacterial strains could be introduced as a sufficient consortium for biodegradation of oil-contaminated soils with similar texture, which is one of the innovative aspects of this research.

An oil-contaminated soil sample with TPH concentration of 1640 mg/kg was subjected to bioremediation during 6 months using indigenous bacterial consortium and a TPH removal efficiency of 28.1% was obtained.

Phenanthrene (PHE) is a polycyclic aromatic hydrocarbon (PAH) with crystalline structure of C14H10, which was produced from incomplete combustion of hydrocarbons and fossil fuels and can cause harmful biological effects. Bioremediation using halophilic bacteria is payed attention over chemical methods due to considerable benefits.

In the present study, a halo-tolerant bacterium Bacillus kochii strain AHV-KH14 was isolated from municipal compost, and used for the bioremediation of PHE from the contaminated soil. The effects of operational parameters including soil/water ratio, initial inoculum size, PHE concentration, and salinity on the bioremediation performance were investigated.

A biodegradation efficiency of about to 98% was obtained for PHE concentration of 50 mg/kg and salinity level of 1.5%. By increasing salinity content PHE concentration, PHE biodegradation rate decreased significantly. It was found that the bioremediation efficiency decreased with increasing PHE concentration. It was also revealed that for the unwashed soil sample, cumulative concentrations of different hydrocarbons played an important role in decreasing the efficiency of bioremediation.

A natural hydrocarbon-contaminated soil sample with total petroleum hydrocarbon (TPH) concentration of 2350 mg/kg was subjected to bioremediation using the selected conditions of operational parameters, and a biodegradation rate of 17.7% was obtained.

The Physical, chemical and biological parameters one of the most important factors determining the quality of drinking water. The overall purpose of this project is to investigate how the quality of water entering the plant in changing the water-color and creating the foams in different units of water purification. 

 This study is a case study and in real scale on the raw water inlet to the Koohsabz drinking water treatment plant has been done. The study was conducted over a period of 6 months (February 2016 to July 2017). In the first stage, the raw water quality was assessed according to standard methods. In the second step, the effect of each of the parameters on the color and foam formation in the water treatment process units and the mechanism of effects have been examined.

Average changes in temperature, turbidity, the color of the water entering the plant during the study period were 15.8oC, 6NTU, and 6TCU respectively and pH ranges from 6.9 to 8.4. Mean change of EC, TOC and DOC respectively is; 765 μS / cm, 5.8mg /l and 3.53mg /l. The average change UV254 and SUVA were 0.178 l / m and 5.856 L/ mg, respectively. Also, the mean changes of humic acid, surfactant, and chlorophyll a in the input raw water were 0.24, 0.05 mg / l and 2.4 μg/m2, respectively.

Investigations showed that the water quality parameters of water entering the treatment plant are effective in creating color and foam in water treatment process units.

The aim of this study was to determine the concentrations of lead (Pb) and cadmium (Cd) in lipstick and eye pencil cosmetics of different grades in the markets of Iran.

This descriptive study was conducted in Ahvaz city in 2018. Sixty different samples of lipstick and eye pencil of three common brands were selected and analyzed using the Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-OES) and the results were compared with standard values recommended by the Food and Drug Administration (FDA). The analysis of lipsticks was based on producer country and colors and producer country only for eye pencil.

The mean concentrations of Pb and Cd were 41.86 and 53.42 µg/g, respectively. Concentrations of lead were higher than those of Cd in lipsticks, while for eye pencil, Cd showed higher concentrations. The overall results indicated that in all brands and colors of lipsticks, only 33% of the samples had Pb content less than the FDA limit, and among lipstick samples, 44% had Cd concentration less than the FDA limit of 3 μg/g, however, in 100% of the eye pencil samples, the concentration of Cd was higher than the recommended value of 3 μg/g.

Given the health risks of exposure to heavy metals and in order to increase community awareness about the harmful effects of cosmetics, it is necessary to monitor the concentration of these toxic elements in these products and encourage the manufactures to meet the FDA standards.

In drinking water treatments, for coagulation and sedimentation of suspended particles, several coagulants are used such as Alum, PAC and ferric chloride. In spite of their positive effect on turbidity removal, these chemicals cause some problems like corrosion and harmful by-products which result in bad effects on human and environmental health. Therefore, finding and using better and more effective materials without such adverse effects is a necessity. The aim of this research was to study the effect of chemically synthetized sodium ferrate (S.F.) in liquid state for the turbidity removal from Zayandehrud River in two conditions: normal turbidity (less than 100 NTU) and high turbidity (more than 900NTU). This research was performed in four states of 30×60, 40×60, 60×60, and 30×40; in each state, one of the water independent variables effective on water turbidity was changed. These four states were S.F. dosing rate, gentile mixing speed, rapid mixing time and pH. For the experiment design, analysis and optimization of independent variables effective on turbidity removal were used. In addition, the surface response method (RSM-D-Optimal) plus Design Expert-v10 optimization software were used for this study. Finally, in this research, according to the standard methods, the residual total Fe (due to sodium ferrate) was checked in the research in order to ensure that its value was in the allowable range for drinking water. The results showed optimum conditions as: pH of 8.5 and gentle mixing oscillating speed of 60rpm for 7min, 50rpm for 7min and 40rpm for 6min, (instead of 40rpm constant speed for 20min) and rapid mixing time of 30s with 120rpm (instead of  60s, which was conventional in Esfahan water treatment plant). In addition, the results showed that by using only 1.54mg/L of S.F. in the above-mentioned optimum condition, the water turbidity removal efficiencies were 95.17% and 99.07% for normal and high turbidity states, respectively. A comparison was made in this research between using S.F. and poly aluminum chloride (PAC) for both normal and high turbidity. The results showed the better effect of S.F. than PAC. The results also showed that the residual total Fe was in the allowable range before and after the filter (because of the reactivity of ferrate with Fe). From the results of this research, it can be concluded that using S.F. has a positive effect, technically and economically, on water turbidity removal (better effect than conventional chemicals) in both normal and high turbidity. Moreover, the results showed that residual total Fe remains in the allowable range.

Ozone can be used as a single technology or in combination with other processes to improve the coagulation- flocculation or biodegradability in order to remove pollutants in natural water treatment. In this study, the effects of pre-ozonation with coagulant substances on the quality parameters of drinking water were investigated using humic acid, kaolin, clay, and green algae in a pilot scale. This study was conducted under laboratory conditions (at both acidic and alkaline pH in different dosages of ozone and coagulant at ozone contact time with simulated water sample (5-20 minutes) in different scenarios). The highest removal efficiency of parameters in the state of pre-ozonation alone and preozonation with a coagulant was observed at contact time of 20 minutes, ozone dosage of 5 g/h, coagulant dosage of 25 mg/L, at alkaline pH along with a decrease in temperature. So that, the average removal rate of turbidity, total organic carbon (TOC), color, and chlorophyll a in contact time of 20 minutes was 76.9%, 52.8%, 66.6%, and 85%, respectively. However, compared to ozonation under similar conditions, the reduction in turbidity, TOC, color, and chlorophyll a was 36.13%, 24.4%, 32.13%, and 79.6%, respectively. Also, it was revealed that pre-ozonation with coagulant could effectively improve the removal of parameters. However, since pre-ozonation can be effectively used to improve the coagulation efficacy in the drinking water treatment, the pre-ozonation combined with coagulation is proposed as an alternative to conventional coagulation to improve the process of drinking water treatment plant.

Background and Contamination of food materials such as rice to mycotoxins (aflatoxin B1 and Ochratoxin A) is a major health concern. This causes more concerns especially in countries that rice is the main food. Nephrotoxic, immunotoxic, mutagenic, teratogenic, and carcinogenic effects of such mycotoxins to human are reported by WHO and EPA. The main objective of current study was to determine the contamination of rice produced in Kohgiluyeh and boyer Ahmad and Khuzestan provinces to aflatoxin B1 and Ochratoxin A.
In a cross-sectional study, 85 samples were randomly collected from rice farms in Basht, Yasuj, Gachsaran and Dena in Kohgiluyeh and Boyer Ahmad province and Ramhormoz in Khuzestan province. Contaminations to Aflatoxin B1 and Ochratoxin A were quantified using ELISA method and data was statistically analyzed by SPSS V18.
The concentration of aflatoxin B1 was less than the limits specified by the Iran National standard and the Union of Europe standard value in 80.58% of the samples. Also, the levels of Ochratoxin A in 100% of the samples were less than standard limits. The average concentrations of aflatoxin B1 and Ochratoxin were 4.70 ng/g and 2.02 ng/g in all samples, respectively. In addition, there was a positive correlation between Aflatoxin B1 and temperature and humidity P=0.001.
This research showed a potential contamination to fungi and its toxins in rice. Increase in temperature and humidity directly increased aflatoxin B1 levels.

The overall objective of this study was to investigate the turbidity and total organic carbon (TOC) of raw water entering the treatment plant and the pre-ozonation unit's efficiency is to remove these compounds. Sampling from raw water and pre-ozonation water was done within 6 months and tested according to the standard method of the method. The results showed that there was a direct correlation between total organic carbon content and turbidity that's more in winter and in February with a high turbidity of 18NTU and TOC above 7mg / l. It was also found that the average pre-ozonation unit efficiency in the removal of total organic carbon with an average ozone dose of 3kg / hr and the contact time 18 minutes, is 20.52%, The highest TOC removal efficiency was in February (35.7%) and the lowest removal efficiency (14.08%) in May. The average turbidity removal efficiency is 61%, the highest and lowest percentages eliminated respectively were in February with 85.2% and 30% in July. Therefore, to increase the efficiency of pre-ozonation unit in removing organic compounds and ... It is necessary to carefully consider the process and design factors To increase the efficiency of removal of compounds.

Cr(IV) is a toxic heavy metal with dangerous effects on health and environment and is discharged through industrial effluents. The main aim of the current study was to determine the efficiency of natural zeolite on removal Cr(IV) from aqueous solutions.
Following the chemical modification of Zeolite, the study variables including pH (2-10), adsorbent dosage (2-20 g/L), reaction time (5-150 min) and Cr(IV) concentration (10-50) were optimized according to the one at the time experimental design. The correlation of obtained data with conventional isotherms and kinetics were also studied.
In optimum pH 2, reaction time of 30 min and adsorbent dosages of 8 g/L, the most removal efficiency of 99.53% was observed for initial Cr(IV) concentration of 10 mg/L. The Freundlich isotherm and pseudo –second order kinetics were better fitted to the findings.
According to findings of current study in lab scale, it can be concluded that natural Zeoliite can be considered as an efficient and cost effective alternative on treatment of effluents containing Cr(IV).

Background and Textile dye effluents have some potential risks which require effective treatment before discharging into the environment. Advanced oxidation processes can remove pollutants faster than other processes due to active hydroxyl radical production; therefore, increase the efficiency of dye removal. This study was aimed at investigating dye removal process using UVA/ZnO and UVA/TiO2 nanocatalysts.
This study was done in a batch reactor on synthetic and real samples and the effects of initial dye concentrations, TiO2 and ZnO nanoparticles dosage, time, pH and interference compounds on efficiency of dye removal was investigated. The Daphnia Magna was used for bioassay test.
The removal rates of dye in optimum conditions were 69% and 95.5% by UVA/ZnO and UVA/TiO2 processes, respectively and the optimum pH in the process was 9 and 2, respectively. In this study, the initial concentration of dye and COD were found to have adverse relation with removal rate of dye in two processes (p The current study showed that TiO2/UVA process with effective optimization of operational factors, has high performance in R.B 86 dye decolorization and reducing toxicity.

Background Chromium and cadmium are two heavy metals having adverse effects on the health and environment, which are released to environment by waste streams. Because of high solubility, they are absorbed by living organisms and through food chain accumulate in human body. This study aimed to determine the efficiency of the polyferric sulfate (PFS) in removing of Cr6 and Cd2 from aqueous solutions.
Methods & Materials This study was investigated in bench scale using a jar test apparatus. The effect of pH (4-11), dose of coagulants (10-200 mg/l), initial amount of metals (1-100 mg/l) and settling time (15-9 min) were investigated. Cr and Cd concentration were determined by atomic absorption spectroscopy.
Results The result showed that the maximum removal efficiency was 52.82% for Cr and 93.13% for Cd, at pH values of 6 and 9, coagulant dosage of 100 and 50 mg/l, respectively, and settling time for 30 min.
Conclusion Coagulation and sedimentation by use of polyferric sulfate can be considered as an efficient process for removal of Cd and pretreatment of Cr.

The biogases are the mixture of gases produced through the microbial decomposition of organic waste which are amply observed in the landfills. The main purpose of this study was to estimate the emission rates of landfill gases such as carbon dioxide, methane and non-methane organic compounds (NMOCs) in the solid waste landfill of Rodan city in Hormozgan province.
All the necessary information such as population, geographic and climate of Rodan city were collected. Solid waste analysis was then conducted. Afterward, the LandGEM software is used in this study for the purpose of estimation of total biogas, methane, carbon dioxide and NMOCs emission from Rodan’s landfill.
The analysis of results showed that only 24.18% of the produced waste in this city is perishable. The calculations indicate that the peak of biogas production which is equal to 420 tons per year would be achieved in the year 2019. The production rates of carbon dioxide and methane in the same year would be equal to 308 and 112 tons per year respectively. The pollutants transmittance calculations in the vicinity of the landfill revealed that the maximum pollutant concentration is within the maximum distance of 200 m.
The results obtained in this study could be used for the purpose of design and installation of extraction or incineration equipment in the landfill of Rodan.

The sequencing batch reactor (SBR) is one of the most widely used systems in sewage treatment because of the simplicity of the process, flexibility of operation in the removal of nutrients, and the ability to be used in different scales. The aim of this study was to evaluate the efficiency of the SBR in the removal of organic matter (nitrogen and phosphorus) from synthetic wastewater at laboratory scale.
In this study, a SBR with a capacity of 24 liters and 24-hour working cycle was used. The sequences of phases consisted of 30 minutes filling, 180 minutes aerobic, 120 minutes anaerobic, 900 minutes aerobic, 180 minutes anaerobic, 20 minutes settle, 5 minute decant, and 5 minutes idle. The initial concentration of nitrogen and phosphorus were 40 and 20 mg/l, respectively. The initial organic load was 0.41 to 0.83 kg chemical oxygen demand (COD)/m3/day. Sampling was carried out in the first aerobic phase and after the third hour anaerobic phase.
Findings: In this system, the average COD removal efficiency in the effluent during these six steps were 65.35%, 92.9%, 95.2%, 93.33%, 96%, and 96.5%, respectively. The results showed that the highest average removal efficiency of organic matter and phosphate phosphorus were 96.5% and 33.05%, respectively, in the sixth stage, and for nitrogen was 34.6% in the first stage.
The results showed the acceptable performance of the SBR in the removal of organic matter and nutrients (P, N).